$border($border-width = 1px 0 0 0, $border-color = #ccc, $border-style = solid, $radius = 0)
    // border-width: $border-width
    //为边框位置提供定位参考
    position relative
    if $$border-width == null {
        $border-width: 0;
    }
    border-radius: $radius
    &::after 
        //用以解决边框layer遮盖内容
        pointer-events: none;
        position: absolute;
        z-index: 999;
        top: 0;
        left: 0;
        //fix当元素宽度出现小数时，边框可能显示不全的问题
        //overflow: hidden
        content: '\0020';
        border-color: $border-color;
        border-style: $border-style;
        border-width: $border-width;
        
       
        @media all and (max--moz-device-pixel-ratio: 1.49),
          (-webkit-max-device-pixel-ratio: 1.49),
          (max-device-pixel-ratio: 1.49),
          (max-resolution: 143dpi),
          (max-resolution: 1.49dppx)
            width: 100%
            height 100%
            if $radius != 0
                border-radius: $radius

        

        @media all and (min--moz-device-pixel-ratio: 1.5) and (max--moz-device-pixel-ratio: 2.49),
          (-webkit-min-device-pixel-ratio: 1.5) and (-webkit-max-device-pixel-ratio: 2.49),
          (min-device-pixel-ratio: 1.5) and (max-device-pixel-ratio: 2.49),
          (min-resolution: 144dpi) and (max-resolution: 239dpi),
          (min-resolution: 1.5dppx) and (max-resolution: 2.49dppx)
            width: 200%
            height 200%
            transform: scale(0.5)
            if $radius != 0
                border-radius: $radius * 2

        @media all and (min--moz-device-pixel-ratio: 2.5),
          (-webkit-min-device-pixel-ratio: 2.5),
          (min-device-pixel-ratio: 2.5),
          (min-resolution: 240dpi),
          (min-resolution: 2.5dppx)
            width: 300%
            height 300%
            transform: scale(0.333333)
            if $radius != 0
                border-radius: $radius * 3
            // transform: scale(0.5)
            //适配dpr进行缩放
            //@indclude responsive(retnalx) {
            //    width: 100%
            //    height: 100%
            //          
            //}


        transform-origin 0 0

    